A Chinese satellite has made a fresh sighting of potential debris from the missing Malaysian Airlines flight MH370 floating in the southern Indian Ocean, with ships being sent urgently to investigate.

The sighted object measured 22.5 metres by 13 metres, and was said to be 75 miles (120km) from possible debris sighted days earlier by Australian satellites.

The official Xinhua news agency said: "The location of the suspicious object is along the southern corridor that missing Malaysia Airlines Flight MH370 might have taken."

The Malaysian defence minister and acting transport minister, Hishammuddin Hussein, said China, one of 26 nations involved in the two-week search for the missing plane, would be releasing more details later.

Planes and vessels are searching an arc of the southern Indian Ocean after Australia announced the satellite sighting of possible debris about 1,550 miles south-west of Perth.

Until the statement from China on Saturday, nothing had been found since the Australian announcement and the search appeared to have become tainted with frustration. Hours earlier a Malaysian minister said the Australian sighting may have been a false lead.

Malaysian officials also expressed concern that the search area would have to be widened again if no trace of the plane was found.

Experts have pointed out that the objects could be unrelated to the plane, one explanation being that they are simply shipping containers that have fallen off a cargo ship in the search area.

However, Australia's deputy prime minister, Warren Truss, appeared to remain optimistic, saying: "Even though this is not a definite lead, it is probably more solid than any other lead around the world and that is why so much effort and interest is being put into this search."

India has officially told Malaysian investigators that it has found no evidence that the plane flew through its airspace, making the latest potential satellite debris sighting more critical. It was the first formal notification that India had come up empty-handed after checking its radar records, sources said.

Earlier, there were farcical scenes as the first Chinese plane heading to Australia to join the search landed at the wrong airport. The Chinese IL-76 military aircraft made an unscheduled stop at Perth International airport before heading to its correct destination at RAAF base Pearce outside the city, where search and rescue operations are being co-ordinated.

The search itself has strained ties between China and Malaysia, with Beijing repeatedly leaning on the south-east Asian country to escalate its hunt and do a better job at looking after the relatives of the Chinese passengers. For families, the process has proved to be an emotionally draining fight to gain information.

Their anxiety has been compounded by reports that they were forced to switch hotels to make way for crews arriving for the Malaysian Grand Prix.

On Saturday, some relatives who had chosen to remain in Beijing accused a Malaysian delegation of concealing the truth and making fools out of the families after they claimed the officials had left a meeting without answering questions.

Police are considering the possibilities of hijacking, sabotage, terrorism or issues related to the mental health of the pilots or anyone else on board.